diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstItem.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstItem.java
index 6c691a629..bc21cbd26 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstItem.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstItem.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code FirstItem} is a {@link KorypheFunction} that returns the first item from a provided
@@ -40,7 +40,7 @@ public T apply(final Iterable<T> input) {
             throw new IllegalArgumentException("Input cannot be null");
         }
         try {
-            return Iterables.getFirst(input, null);
+            return IterableUtil.getFirst(input);
         } finally {
             CloseableUtil.close(input);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstValid.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstValid.java
index 6c4553b50..2d88b6a19 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstValid.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FirstValid.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package uk.gov.gchq.koryphe.impl.function;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Iterables;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
@@ -25,6 +24,7 @@
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 import java.util.function.Predicate;
 
@@ -53,7 +53,7 @@ public FirstValid(final Predicate predicate) {
     public I_ITEM apply(final Iterable<I_ITEM> iterable) {
         if (nonNull(iterable) && nonNull(predicate)) {
             try {
-                return Iterables.getFirst(filter(iterable, predicate), null);
+                return IterableUtil.getFirst(filter(iterable, predicate));
             } finally {
                 CloseableUtil.close(iterable);
             }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FunctionChain.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FunctionChain.java
index a91071ed6..50e8111dc 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FunctionChain.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/FunctionChain.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2022 Crown Copyright
+ * Copyright 2019-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package uk.gov.gchq.koryphe.impl.function;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Lists;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
@@ -25,6 +24,7 @@
 import uk.gov.gchq.koryphe.tuple.function.TupleAdaptedFunction;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
@@ -43,7 +43,7 @@ public FunctionChain() {
     }
 
     public FunctionChain(final Function... functions) {
-        this(Lists.newArrayList(functions));
+        this(Arrays.asList(functions));
     }
 
     public FunctionChain(final List<Function> functions) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/IsEmpty.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/IsEmpty.java
index e482a5edb..946bb7d15 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/IsEmpty.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/IsEmpty.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code IsEmpty} is a {@link KorypheFunction} which returns a boolean based
@@ -38,7 +38,7 @@ public Boolean apply(final Iterable input) {
             throw new IllegalArgumentException("Input cannot be null");
         }
         try {
-            return Iterables.isEmpty(input);
+            return IterableUtil.isEmpty(input);
         } finally {
             CloseableUtil.close(input);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/LastItem.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/LastItem.java
index 5411b64a7..3bb8dea95 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/LastItem.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/LastItem.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code LastItem} is a {@link KorypheFunction} that returns the last item from a provided
@@ -41,7 +41,7 @@ public T apply(final Iterable<T> input) {
             throw new IllegalArgumentException("Input cannot be null");
         }
         try {
-            return Iterables.getLast(input, null);
+            return IterableUtil.getLast(input);
         } finally {
             CloseableUtil.close(input);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Length.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Length.java
index c442f238a..283fbdda2 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Length.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Length.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
@@ -58,9 +57,9 @@ public Integer apply(final Object value) {
             length = ((Object[]) value).length;
         } else if (value instanceof Iterable) {
             if (null != maxLength) {
-                length = Iterables.size(IterableUtil.limit((Iterable) value, 0, maxLength, true));
+                length = IterableUtil.size(IterableUtil.limit((Iterable) value, 0, maxLength, true));
             } else {
-                length = Iterables.size((Iterable) value);
+                length = IterableUtil.size((Iterable) value);
             }
         } else if (value instanceof Map) {
             length = ((Map) value).size();
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/NthItem.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/NthItem.java
index 3038a16a4..0bbdcb5cf 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/NthItem.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/NthItem.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
@@ -25,6 +24,7 @@
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code NthItem} is a {@link KorypheFunction} that returns an item based on user selection,
@@ -53,7 +53,7 @@ public T apply(final Iterable<T> input) {
             throw new IllegalArgumentException("Input cannot be null");
         }
         try {
-            return Iterables.get(input, selection);
+            return IterableUtil.toList(input).get(selection);
         } finally {
             CloseableUtil.close(input);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Size.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Size.java
index 91a169753..7658e862b 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Size.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/Size.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.util.CloseableUtil;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code Size} is a {@link KorypheFunction} which returns the size of a provided
@@ -38,7 +38,7 @@ public Integer apply(final Iterable input) {
             throw new IllegalArgumentException("Input cannot be null");
         }
         try {
-            return Iterables.size(input);
+            return IterableUtil.size(input);
         } finally {
             CloseableUtil.close(input);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToArray.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToArray.java
index a7fda7f7d..142d62182 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToArray.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToArray.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,10 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
-
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 /**
  * A {@code ToArray} is a {@link java.util.function.Function} that takes
@@ -43,7 +42,7 @@ public Object[] apply(final Object value) {
         }
 
         if (value instanceof Iterable) {
-            return Iterables.toArray(((Iterable) value), Object.class);
+            return IterableUtil.toList(((Iterable) value)).toArray();
         }
 
         return new Object[]{value};
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToBytes.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToBytes.java
index 2747f1fa1..6ade83c2a 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToBytes.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToBytes.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 Crown Copyright
+ * Copyright 2019-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,7 +19,6 @@
 import com.fasterxml.jackson.annotation.JsonGetter;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonSetter;
-import com.google.common.base.Charsets;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
@@ -30,6 +29,7 @@
 
 import java.nio.charset.Charset;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Objects.isNull;
 import static java.util.Objects.nonNull;
 
@@ -41,7 +41,7 @@
 @Since("1.8.0")
 @Summary("Extracts the bytes from a string")
 public class ToBytes extends KorypheFunction<String, byte[]> {
-    public static final Charset DEFAULT_CHARSET = Charsets.UTF_8;
+    public static final Charset DEFAULT_CHARSET = UTF_8;
 
     @JsonInclude(JsonInclude.Include.NON_DEFAULT)
     private Charset charset;
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToList.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToList.java
index b0be16262..aafee889a 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToList.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToList.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -37,20 +38,17 @@ public class ToList extends KorypheFunction<Object, List<?>> {
     @Override
     public List<?> apply(final Object value) {
         if (null == value) {
-            return Lists.newArrayList((Object) null);
+            return Arrays.asList((Object) null);
         }
 
         if (value instanceof Object[]) {
-            return Lists.newArrayList((Object[]) value);
+            return new ArrayList<>(Arrays.asList((Object[]) value));
         }
 
         if (value instanceof Iterable) {
-            if (value instanceof List) {
-                return (List<?>) value;
-            }
-            return Lists.newArrayList((Iterable) value);
+            return IterableUtil.toList((Iterable) value);
         }
 
-        return Lists.newArrayList(value);
+        return new ArrayList<>(Arrays.asList(value));
     }
 }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToSet.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToSet.java
index 1ad1077ce..fb183fc9c 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToSet.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToSet.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,13 +19,14 @@
 import com.fasterxml.jackson.annotation.JsonGetter;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonSetter;
-import com.google.common.collect.Sets;
 
 import uk.gov.gchq.koryphe.Since;
 import uk.gov.gchq.koryphe.Summary;
 import uk.gov.gchq.koryphe.function.KorypheFunction;
 import uk.gov.gchq.koryphe.serialisation.json.SimpleClassNameIdResolver;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.TreeSet;
@@ -76,9 +77,9 @@ public Set<?> apply(final Object value) {
         } else if (implementation.isInstance(value)) {
            return (Set) value;
         } else if (value instanceof Object[]) {
-            setImpl.addAll(Sets.newHashSet((Object[]) value));
+            setImpl.addAll(new HashSet<>(Arrays.asList((Object[]) value)));
         } else if (value instanceof Iterable) {
-            setImpl.addAll(Sets.newHashSet((Iterable) value));
+            setImpl.addAll(new HashSet<>(IterableUtil.toList((Iterable) value)));
         } else {
             setImpl.add(value);
         }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToString.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToString.java
index 5f2e8ea94..e98307bb9 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToString.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/function/ToString.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,7 +19,6 @@
 import com.fasterxml.jackson.annotation.JsonGetter;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonSetter;
-import com.google.common.base.Charsets;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
@@ -30,6 +29,7 @@
 import java.nio.charset.Charset;
 import java.util.Arrays;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Objects.nonNull;
 
 /**
@@ -40,7 +40,7 @@
 @Since("1.0.0")
 @Summary("Calls ToString on an object")
 public class ToString extends KorypheFunction<Object, String> {
-    public static final Charset DEFAULT_CHARSET = Charsets.UTF_8;
+    public static final Charset DEFAULT_CHARSET = UTF_8;
 
     private Charset charset;
 
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/And.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/And.java
index 47d14eaec..7685b827b 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/And.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/And.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package uk.gov.gchq.koryphe.impl.predicate;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Lists;
 import org.apache.commons.lang3.builder.ToStringBuilder;
 
 import uk.gov.gchq.koryphe.Since;
@@ -25,6 +24,7 @@
 import uk.gov.gchq.koryphe.predicate.PredicateComposite;
 import uk.gov.gchq.koryphe.tuple.predicate.IntegerTupleAdaptedPredicate;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Predicate;
 
@@ -42,7 +42,7 @@ public And() {
     }
 
     public And(final Predicate<?>... predicates) {
-        this(Lists.newArrayList(predicates));
+        this(Arrays.asList(predicates));
     }
 
     public And(final List<Predicate> predicates) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/AreIn.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/AreIn.java
index 2e4f1578a..1ab5a2afb 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/AreIn.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/AreIn.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,6 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Sets;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.apache.commons.lang3.builder.ToStringBuilder;
@@ -62,7 +61,7 @@ public AreIn(final Collection<?> allowedValues, final boolean nullOrEmptyAllowed
     }
 
     public AreIn(final Object... allowedValues) {
-        this.allowedValues = Sets.newHashSet(allowedValues);
+        this.allowedValues = new HashSet<>(Arrays.asList(allowedValues));
     }
 
     @JsonIgnore
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/IsIn.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/IsIn.java
index e5300b63e..a9805fd14 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/IsIn.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/IsIn.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,7 +19,6 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Sets;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.apache.commons.lang3.builder.ToStringBuilder;
@@ -51,7 +50,7 @@ public IsIn(final Collection<Object> controlData) {
     }
 
     public IsIn(final Object... controlData) {
-        this.allowedValues = Sets.newHashSet(controlData);
+        this.allowedValues = new HashSet<>(Arrays.asList(controlData));
     }
 
     @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.WRAPPER_OBJECT)
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/Or.java b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/Or.java
index 8cf5f1b39..14a71398a 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/Or.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/Or.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package uk.gov.gchq.koryphe.impl.predicate;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
-import com.google.common.collect.Lists;
 import org.apache.commons.lang3.builder.ToStringBuilder;
 
 import uk.gov.gchq.koryphe.Since;
@@ -27,6 +26,7 @@
 import uk.gov.gchq.koryphe.tuple.predicate.IntegerTupleAdaptedPredicate;
 import uk.gov.gchq.koryphe.tuple.predicate.TupleAdaptedPredicate;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Predicate;
 
@@ -44,7 +44,7 @@ public Or() {
     }
 
     public Or(final Predicate<?>... predicates) {
-        this(Lists.newArrayList(predicates));
+        this(Arrays.asList(predicates));
     }
 
     public Or(final List<Predicate> predicates) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/iterable/FilteredIterable.java b/core/src/main/java/uk/gov/gchq/koryphe/iterable/FilteredIterable.java
index 14e3905d3..371f1fd17 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/iterable/FilteredIterable.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/iterable/FilteredIterable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,10 @@
 
 package uk.gov.gchq.koryphe.iterable;
 
-import com.google.common.collect.Lists;
-
 import uk.gov.gchq.koryphe.util.CloseableUtil;
 
 import java.io.Closeable;
+import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
@@ -38,7 +37,7 @@ public class FilteredIterable<T> implements Closeable, Iterable<T> {
     private final List<Predicate> predicates;
 
     public FilteredIterable(final Iterable<T> iterable, final Predicate... predicates) {
-        this(iterable, Lists.newArrayList(predicates));
+        this(iterable, Arrays.asList(predicates));
     }
 
     public FilteredIterable(final Iterable<T> iterable, final List<Predicate> predicates) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/iterable/MappedIterable.java b/core/src/main/java/uk/gov/gchq/koryphe/iterable/MappedIterable.java
index c45a51ec5..cc3660b22 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/iterable/MappedIterable.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/iterable/MappedIterable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,10 @@
 
 package uk.gov.gchq.koryphe.iterable;
 
-import com.google.common.collect.Lists;
-
 import uk.gov.gchq.koryphe.util.CloseableUtil;
 
 import java.io.Closeable;
+import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
@@ -39,7 +38,7 @@ public class MappedIterable<I_ITEM, O_ITEM> implements Closeable, Iterable<O_ITE
     private final List<Function> functions;
 
     public MappedIterable(final Iterable<I_ITEM> iterable, final Function... functions) {
-        this(iterable, Lists.newArrayList(functions));
+        this(iterable, Arrays.asList(functions));
     }
 
     public MappedIterable(final Iterable<I_ITEM> iterable, final List<Function> functions) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/serialisation/json/SimpleClassNameCache.java b/core/src/main/java/uk/gov/gchq/koryphe/serialisation/json/SimpleClassNameCache.java
index 85afd8edf..fa52113d3 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/serialisation/json/SimpleClassNameCache.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/serialisation/json/SimpleClassNameCache.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2022 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,13 +17,14 @@
 package uk.gov.gchq.koryphe.serialisation.json;
 
 import com.fasterxml.jackson.databind.JavaType;
-import com.google.common.collect.Sets;
 import org.apache.commons.lang3.StringUtils;
 
 import uk.gov.gchq.koryphe.util.JavaUtils;
 import uk.gov.gchq.koryphe.util.ReflectionUtil;
 
+import java.util.Arrays;
 import java.util.Comparator;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -189,7 +190,7 @@ public static String getSimpleClassNameOrNull(final Class<?> clazz) {
                 final Package classPackage = nonArrayClass.getPackage();
                 if (null != classPackage && corePackages.contains(classPackage.getName())) {
                     // Found the class, so cache the result for next time.
-                    addIdClasses(id, Sets.newHashSet(nonArrayClass));
+                    addIdClasses(id, new HashSet<>(Arrays.asList((nonArrayClass))));
                 } else {
                     id = null;
                 }
@@ -244,7 +245,7 @@ public static String getClassName(final String id, final JavaType baseType) {
                     final Class<?> clazz = ReflectionUtil.getClassFromName(classNameTmp);
                     if (null != clazz) {
                         className = classNameTmp;
-                        addIdClasses(nonArrayId, Sets.newHashSet(clazz));
+                        addIdClasses(nonArrayId, new HashSet<>(Arrays.asList(clazz)));
                         break;
                     }
                 }
@@ -354,7 +355,7 @@ private static void addSimpleClassName(final Map<String, Set<Class>> map, final
         final String id = StringUtils.capitalize(clazz.getSimpleName());
         final Set<Class> value = map.get(id);
         if (null == value) {
-            map.put(id, Sets.newHashSet(clazz));
+            map.put(id, new HashSet<>(Arrays.asList(clazz)));
         } else {
             value.add(clazz);
         }
@@ -366,7 +367,7 @@ private static void addSimpleClassNames(final Map<String, Set<Class>> map, final
             final String id = StringUtils.capitalize(entry.getKey());
             final Set<Class> value = map.get(id);
             if (null == value) {
-                map.put(id, Sets.newHashSet(entry.getValue()));
+                map.put(id, entry.getValue());
             } else {
                 value.addAll(entry.getValue());
             }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/tuple/ArrayTuple.java b/core/src/main/java/uk/gov/gchq/koryphe/tuple/ArrayTuple.java
index a1477c7d5..44e58c252 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/tuple/ArrayTuple.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/tuple/ArrayTuple.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,13 @@
 
 package uk.gov.gchq.koryphe.tuple;
 
-import com.google.common.collect.Iterables;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.apache.commons.lang3.builder.ToStringBuilder;
 
+import uk.gov.gchq.koryphe.util.IterableUtil;
+
 import java.util.Arrays;
 import java.util.Iterator;
 
@@ -43,7 +44,7 @@ public ArrayTuple(final Object... values) {
     }
 
     public ArrayTuple(final Iterable<?> values) {
-        this(Iterables.toArray(values, Object.class));
+        this(IterableUtil.toList(values).toArray());
     }
 
     /**
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/util/IterableUtil.java b/core/src/main/java/uk/gov/gchq/koryphe/util/IterableUtil.java
index 3aadc445c..9b17de460 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/util/IterableUtil.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/util/IterableUtil.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,10 +21,14 @@
 import uk.gov.gchq.koryphe.iterable.LimitedIterable;
 import uk.gov.gchq.koryphe.iterable.MappedIterable;
 
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.stream.StreamSupport;
 
 /**
  * An {@code IterableUtil} is a utility class providing capabilities for:
@@ -87,4 +91,35 @@ public static <T> Iterable<T> limit(final Iterable<T> iterable, final int start,
         return new LimitedIterable<>(iterable, start, end, truncate);
     }
 
+    public static int size(final Iterable<?> iterable) {
+        if (iterable instanceof Collection) {
+            return ((Collection<?>) iterable).size();
+        }
+        return (int) StreamSupport.stream(iterable.spliterator(), false).count();
+    }
+
+    public static <T> List<T> toList(final Iterable<T> iterable) {
+        if (iterable instanceof List) {
+            return (List<T>) iterable;
+        }
+        if (iterable instanceof Set) {
+            return new ArrayList<>((Set<T>) iterable);
+        }
+        List<T> asList = new ArrayList<>();
+        iterable.forEach(asList::add);
+        return asList;
+    }
+
+    public static boolean isEmpty(final Iterable<?> iterable) {
+        return size(iterable) == 0;
+    }
+
+    public static <T> T getFirst(final Iterable<T> iterable) {
+        return iterable.iterator().next();
+    }
+
+    public static <T> T getLast(final Iterable<T> iterable) {
+        List<T> list = toList(iterable);
+        return list.get(list.size() - 1);
+    }
 }
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/util/JavaUtils.java b/core/src/main/java/uk/gov/gchq/koryphe/util/JavaUtils.java
index c115abbf2..9f9970c6a 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/util/JavaUtils.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/util/JavaUtils.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 
 package uk.gov.gchq.koryphe.util;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 
@@ -41,7 +42,7 @@ public static class Set {
 
         @SafeVarargs
         public static <T> java.util.Set<T> of(final T... item) {
-            return Collections.unmodifiableSet(com.google.common.collect.Sets.newHashSet(item));
+            return Collections.unmodifiableSet(new HashSet<>(Arrays.asList(item)));
         }
 
         public static <T> java.util.Set<T> copyOf(final java.util.Set<T> set) {
diff --git a/core/src/main/java/uk/gov/gchq/koryphe/util/ReflectionUtil.java b/core/src/main/java/uk/gov/gchq/koryphe/util/ReflectionUtil.java
index 69b731527..e46a8a83f 100644
--- a/core/src/main/java/uk/gov/gchq/koryphe/util/ReflectionUtil.java
+++ b/core/src/main/java/uk/gov/gchq/koryphe/util/ReflectionUtil.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2022 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,11 @@
 
 package uk.gov.gchq.koryphe.util;
 
-import com.google.common.collect.Sets;
 import io.github.lukehutch.fastclasspathscanner.FastClasspathScanner;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Modifier;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -209,7 +209,7 @@ public static void addReflectionPackages(final String... newPackages) {
             if (1 == newPackages.length) {
                 addReflectionPackages(Collections.singleton(newPackages[0]));
             } else {
-                addReflectionPackages(Sets.newHashSet(newPackages));
+                addReflectionPackages(new HashSet<>(Arrays.asList(newPackages)));
             }
         }
     }
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DefaultIfEmptyTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DefaultIfEmptyTest.java
index e968a8b4f..fdebc86d8 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DefaultIfEmptyTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DefaultIfEmptyTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -101,7 +101,7 @@ public void shouldReturnDefaultValueIfEmpty() {
     @Test
     public void shouldReturnOriginalValueIfNotEmpty() {
         // Given
-        final List<String> iterable = Lists.newArrayList("first", "second");
+        final List<String> iterable = Arrays.asList("first", "second");
         final DefaultIfEmpty defaultIfEmpty = new DefaultIfEmpty(DEFAULT_VALUE);
 
         // When
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DictionaryLookupTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DictionaryLookupTest.java
index c1c38162b..988a7acf8 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DictionaryLookupTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/DictionaryLookupTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 Crown Copyright
+ * Copyright 2019-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Maps;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -82,7 +81,7 @@ protected DictionaryLookup<String, Integer> getInstance() {
     protected Iterable<DictionaryLookup<?, ?>> getDifferentInstancesOrNull() {
         return Arrays.asList(
                 new DictionaryLookup<>(null),
-                new DictionaryLookup<>(Maps.newHashMap())
+                new DictionaryLookup<>(new HashMap<>())
         );
     }
 
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ExtractValuesTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ExtractValuesTest.java
index e9eee0571..9be1d2199 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ExtractValuesTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ExtractValuesTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Iterables;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/FunctionChainTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/FunctionChainTest.java
index 56266d7ce..85c3073be 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/FunctionChainTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/FunctionChainTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 Crown Copyright
+ * Copyright 2019-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
@@ -25,6 +24,7 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.HashSet;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.InstanceOfAssertFactories.ARRAY;
@@ -98,7 +98,7 @@ public void shouldApplyAllTupleFunctions() {
         assertThat(result)
                 .extracting("values")
                 .asInstanceOf(ARRAY)
-                .containsExactly("someString", "SOMESTRING", Sets.newHashSet("SOMESTRING"));
+                .containsExactly("someString", "SOMESTRING", new HashSet<>(Arrays.asList("SOMESTRING")));
     }
 
     @Test
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IsEmptyTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IsEmptyTest.java
index 39ce996c6..7e3240c60 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IsEmptyTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IsEmptyTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
@@ -24,6 +23,7 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.HashSet;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
@@ -74,7 +74,7 @@ public void shouldJsonSerialiseAndDeserialise() throws IOException {
     public void shouldReturnTrueForEmptyIterable() {
         // Given
         final IsEmpty function = new IsEmpty();
-        final Iterable input = Sets.newHashSet();
+        final Iterable input = new HashSet<>(Arrays.asList());
 
         // When
         final Boolean result = function.apply(input);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFilterTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFilterTest.java
index 7c0cccf3b..cf1297594 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFilterTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFilterTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFlattenTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFlattenTest.java
index c4a96a30a..f7aca9e75 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFlattenTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableFlattenTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
@@ -26,7 +24,9 @@
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -51,7 +51,7 @@ public void shouldHandleNullInput() {
     public void shouldFlattenIterableNumbers() {
         // Given
         final IterableFlatten<Number> function = new IterableFlatten<>(new Sum());
-        final List<Number> input = Lists.newArrayList(1, 2, 3, 4, 5);
+        final List<Number> input = Arrays.asList(1, 2, 3, 4, 5);
 
         // When
         final Number result = function.apply(input);
@@ -64,7 +64,7 @@ public void shouldFlattenIterableNumbers() {
     public void shouldFlattenIterableNumbersWithNull() {
         // Given
         final IterableFlatten<Number> function = new IterableFlatten<>(new Sum());
-        final List<Number> input = Lists.newArrayList(2, 4, 6, 8, null, 10);
+        final List<Number> input = Arrays.asList(2, 4, 6, 8, null, 10);
 
         // When
         final Number result = function.apply(input);
@@ -76,7 +76,7 @@ public void shouldFlattenIterableNumbersWithNull() {
     public void shouldFlattenIterableNumbersAllNull() {
         // Given
         final IterableFlatten<Number> function = new IterableFlatten<>(new Sum());
-        final List<Number> input = Lists.newArrayList(null, null, null, null);
+        final List<Number> input = Arrays.asList(null, null, null, null);
 
         // When
         final Number result = function.apply(input);
@@ -89,7 +89,7 @@ public void shouldFlattenIterableNumbersAllNull() {
     public void shouldFlattenIterableStrings() {
         // Given
         final IterableFlatten<String> function = new IterableFlatten<>((a, b) -> a + b);
-        final Set<String> input = Sets.newHashSet("a", "b", "c");
+        final Set<String> input = new HashSet<>(Arrays.asList("a", "b", "c"));
 
         // When
         final String result = function.apply(input);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableLongestTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableLongestTest.java
index 4d63896af..f97b26382 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableLongestTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/IterableLongestTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -45,7 +45,7 @@ public void shouldHandleNullInput() {
     public void shouldGetLongestItemFromList() {
         // Given
         final IterableLongest function = getInstance();
-        final List<String> list = Lists.newArrayList("a", "ab", "abc");
+        final List<String> list = Arrays.asList("a", "ab", "abc");
 
         // When
         final Object result = function.apply(list);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/LongestTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/LongestTest.java
index d70a474f3..86a7bc165 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/LongestTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/LongestTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,16 +16,16 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -92,8 +92,8 @@ public void shouldReturnLongestObjectArrayInput() {
     public void shouldReturnLongestListInput() {
         // Given
         final Longest<List<Integer>> function = new Longest<>();
-        final List<Integer> input1 = Lists.newArrayList(1);
-        final List<Integer> input2 = Lists.newArrayList(1, 2, 3);
+        final List<Integer> input1 = Arrays.asList(1);
+        final List<Integer> input2 = Arrays.asList(1, 2, 3);
 
         // When
         final List<Integer> result = function.apply(input1, input2);
@@ -106,8 +106,8 @@ public void shouldReturnLongestListInput() {
     public void shouldReturnLongestSetInput() {
         // Given
         final Longest<Set<Integer>> function = new Longest<>();
-        final Set<Integer> input1 = Sets.newHashSet(1);
-        final Set<Integer> input2 = Sets.newHashSet(1, 2, 3);
+        final Set<Integer> input1 = new HashSet<>(Arrays.asList(1));
+        final Set<Integer> input2 = new HashSet<>(Arrays.asList(1, 2, 3));
 
         // When
         final Set<Integer> result = function.apply(input1, input2);
@@ -121,7 +121,7 @@ public void shouldReturnLongestMapInput() {
         // Given
         final Longest<Map<String, String>> function = new Longest<>();
         final Map<String, String> input1 = new HashMap<>();
-        final Map<String, String> input2 = Maps.asMap(Sets.newHashSet("1"), k -> k);
+        final Map<String, String> input2 = Collections.singletonMap("1", "1");
 
         // When
         final Map<String, String> result = function.apply(input1, input2);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/StringJoinTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/StringJoinTest.java
index 180abb94c..733846e45 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/StringJoinTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/StringJoinTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 Crown Copyright
+ * Copyright 2020-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,15 +16,15 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -48,7 +48,7 @@ public void shouldHandleNullInput() {
     public void shouldHandleNullDelimiter() {
         // Given
         final StringJoin<String> function = new StringJoin<>(null);
-        final Set<String> input = Sets.newHashSet("a", "b", "c");
+        final Set<String> input = new HashSet<>(Arrays.asList("a", "b", "c"));
 
         // When
         final String result = function.apply(input);
@@ -61,7 +61,7 @@ public void shouldHandleNullDelimiter() {
     public void shouldJoinIterableOfStrings() {
         // Given
         final StringJoin<String> function = new StringJoin<>();
-        final Set<String> input = Sets.newHashSet("a", "b", "c");
+        final Set<String> input = new HashSet<>(Arrays.asList("a", "b", "c"));
 
         // When
         final String result = function.apply(input);
@@ -74,7 +74,7 @@ public void shouldJoinIterableOfStrings() {
     public void shouldJoinIterableOfIntegers() {
         // Given
         final StringJoin<Integer> function = new StringJoin<>();
-        final List<Integer> input = Lists.newArrayList(1, 2, 3, 4, 5);
+        final List<Integer> input = Arrays.asList(1, 2, 3, 4, 5);
 
         // When
         final String result = function.apply(input);
@@ -87,7 +87,7 @@ public void shouldJoinIterableOfIntegers() {
     public void shouldJoinIterableOfStringsWithDelimiter() {
         // Given
         final StringJoin<String> function = new StringJoin<>(",");
-        final Set<String> input = Sets.newHashSet("a", "b", "c");
+        final Set<String> input = new HashSet<>(Arrays.asList("a", "b", "c"));
 
         // When
         final String result = function.apply(input);
@@ -100,7 +100,7 @@ public void shouldJoinIterableOfStringsWithDelimiter() {
     public void shouldJoinIterableOfIntegersWithDelimiter() {
         // Given
         final StringJoin<Integer> function = new StringJoin<>(" ");
-        final List<Integer> input = Lists.newArrayList(1, 2, 3, 4, 5);
+        final List<Integer> input = Arrays.asList(1, 2, 3, 4, 5);
 
         // When
         final String result = function.apply(input);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToArrayTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToArrayTest.java
index 4cb53db53..7ec616c8a 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToArrayTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToArrayTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
@@ -25,6 +23,7 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.LinkedHashSet;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -59,7 +58,7 @@ public void shouldConvertStringToArray() {
     public void shouldConvertListToArray() {
         // Given
         final ToArray function = new ToArray();
-        final Object value = Lists.newArrayList("value1", "value2");
+        final Object value = Arrays.asList("value1", "value2");
 
         // When
         final Object[] result = function.apply(value);
@@ -72,7 +71,7 @@ public void shouldConvertListToArray() {
     public void shouldConvertSetToArray() {
         // Given
         final ToArray function = new ToArray();
-        final Object value = Sets.newLinkedHashSet(Arrays.asList("value1", "value2"));
+        final Object value = new LinkedHashSet<>(Arrays.asList("value1", "value2"));
 
         // When
         final Object[] result = function.apply(value);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToListTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToListTest.java
index b68a6cc59..04d40d4bb 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToListTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToListTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
@@ -26,6 +24,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -43,7 +42,7 @@ public void shouldConvertNullToList() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Lists.newArrayList((Object) null))
+                .isEqualTo(Arrays.asList((Object) null))
                 .asList()
                 .isNotNull()
                 .isNotEmpty()
@@ -61,7 +60,7 @@ public void shouldConvertStringToList() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Lists.newArrayList(value))
+                .isEqualTo(Arrays.asList(value))
                 .isExactlyInstanceOf(ArrayList.class)
                 .asList()
                 .containsExactly(value);
@@ -78,24 +77,24 @@ public void shouldConvertArrayToList() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Lists.newArrayList((Object []) value))
+                .isEqualTo(Arrays.asList((Object[]) value))
                 .isExactlyInstanceOf(ArrayList.class)
                 .asList()
-                .containsExactlyElementsOf(Lists.newArrayList((Object[]) value));
+                .containsExactlyElementsOf(Arrays.asList((Object[]) value));
     }
 
     @Test
     public void shouldConvertSetToList() {
         // Given
         final ToList function = new ToList();
-        final Set<String> value = Sets.newLinkedHashSet(Arrays.asList("value1", "value2"));
+        final Set<String> value = new LinkedHashSet<>(Arrays.asList("value1", "value2"));
 
         // When
         final Object result = function.apply(value);
 
         // Then
         assertThat(result)
-                .isEqualTo(Lists.newArrayList(value))
+                .isEqualTo(new ArrayList<>(value))
                 .isExactlyInstanceOf(ArrayList.class)
                 .asList()
                 .containsExactlyElementsOf(value);
@@ -105,7 +104,7 @@ public void shouldConvertSetToList() {
     public void shouldReturnAGivenList() {
         // Given
         final ToList function = new ToList();
-        final Object value = Lists.newArrayList("value1", "value2");
+        final Object value = Arrays.asList("value1", "value2");
 
         // When
         final Object result = function.apply(value);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToSetTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToSetTest.java
index 6a0c7b4c0..34d260e72 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToSetTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToSetTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2022 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +16,13 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.function.FunctionTest;
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -47,7 +46,7 @@ public void shouldConvertNullToHashSet() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Sets.newHashSet((Object) null))
+                .isEqualTo(new HashSet<>(Arrays.asList((Object) null)))
                 .asInstanceOf(COLLECTION)
                 .isNotNull()
                 .isNotEmpty()
@@ -65,7 +64,7 @@ public void shouldConvertNullToEmptyTreeSet() {
         // Then
         assertThat(result)
                 .isExactlyInstanceOf(TreeSet.class)
-                .isEqualTo(Sets.newTreeSet())
+                .isEqualTo(new TreeSet<>())
                 .asInstanceOf(COLLECTION)
                 .isEmpty();
     }
@@ -81,7 +80,7 @@ public void shouldConvertStringToHashSet() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Sets.newHashSet(value))
+                .isEqualTo(new HashSet<>(Arrays.asList(value)))
                 .isExactlyInstanceOf(HashSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactly(value);
@@ -98,7 +97,7 @@ public void shouldConvertStringToTreeSet() {
 
         // Then
         assertThat(result)
-                .isEqualTo(new TreeSet(Sets.newHashSet(value)))
+                .isEqualTo(new TreeSet(new HashSet<>(Arrays.asList(value))))
                 .isExactlyInstanceOf(TreeSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactly(value);
@@ -115,7 +114,7 @@ public void shouldConvertStringToTreeSetUsingfullyQualifiedClassString() throws
 
         // Then
         assertThat(result)
-                .isEqualTo(new TreeSet(Sets.newHashSet(value)))
+                .isEqualTo(new TreeSet(new HashSet<>(Arrays.asList(value))))
                 .isExactlyInstanceOf(TreeSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactly(value);
@@ -132,7 +131,7 @@ public void shouldConvertStringToTreeSetUsingSimpleClassString() throws ClassNot
 
         // Then
         assertThat(result)
-                .isEqualTo(new TreeSet(Sets.newHashSet(value)))
+                .isEqualTo(new TreeSet(new HashSet<>(Arrays.asList(value))))
                 .isExactlyInstanceOf(TreeSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactly(value);
@@ -149,10 +148,10 @@ public void shouldConvertArrayToHashSet() {
 
         // Then
         assertThat(result)
-                .isEqualTo(Sets.newHashSet((Object[]) value))
+                .isEqualTo(new HashSet<>(Arrays.asList((Object[]) value)))
                 .isExactlyInstanceOf(HashSet.class)
                 .asInstanceOf(COLLECTION)
-                .containsExactlyInAnyOrderElementsOf(Lists.newArrayList((Object[]) value));
+                .containsExactlyInAnyOrderElementsOf(Arrays.asList((Object[]) value));
     }
 
     @Test
@@ -166,24 +165,24 @@ public void shouldConvertArrayToTreeSet() {
 
         // Then
         assertThat(result)
-                .isEqualTo(new TreeSet(Sets.newHashSet((Object[]) value)))
+                .isEqualTo(new TreeSet(new HashSet<>(Arrays.asList((Object[]) value))))
                 .isExactlyInstanceOf(TreeSet.class)
                 .asInstanceOf(COLLECTION)
-                .containsExactlyInAnyOrderElementsOf(Lists.newArrayList((Object[]) value));
+                .containsExactlyInAnyOrderElementsOf(Arrays.asList((Object[]) value));
     }
 
     @Test
     public void shouldConvertListToHashSet() {
         // Given
         final ToSet function = new ToSet();
-        final List<String> value = Lists.newArrayList("value1", "value2");
+        final List<String> value = Arrays.asList("value1", "value2");
 
         // When
         final Object result = function.apply(value);
 
         // Then
         assertThat(result)
-                .isEqualTo(Sets.newHashSet(value))
+                .isEqualTo(new HashSet<>(value))
                 .isExactlyInstanceOf(HashSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactlyInAnyOrderElementsOf(value);
@@ -193,14 +192,14 @@ public void shouldConvertListToHashSet() {
     public void shouldConvertListToTreeSet() {
         // Given
         final ToSet function = new ToSet(TreeSet.class);
-        final List<String> value = Lists.newArrayList("value1", "value2");
+        final List<String> value = Arrays.asList("value1", "value2");
 
         // When
         final Object result = function.apply(value);
 
         // Then
         assertThat(result)
-                .isEqualTo(new TreeSet(Sets.newHashSet(value)))
+                .isEqualTo(new TreeSet(new HashSet<>(value)))
                 .isExactlyInstanceOf(TreeSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactlyInAnyOrderElementsOf(value);
@@ -210,7 +209,7 @@ public void shouldConvertListToTreeSet() {
     public void shouldReturnAGivenHashSet() {
         // Given
         final ToSet function = new ToSet();
-        final Object value = Sets.newHashSet("value1", "value2");
+        final Object value = new HashSet<>(Arrays.asList("value1", "value2"));
 
         // When
         final Object result = function.apply(value);
@@ -223,7 +222,7 @@ public void shouldReturnAGivenHashSet() {
     public void shouldReturnAGivenTreeSet() {
         // Given
         final ToSet function = new ToSet(TreeSet.class);
-        final Object value = new TreeSet(Sets.newHashSet("value1", "value2"));
+        final Object value = new TreeSet(new HashSet<>(Arrays.asList("value1", "value2")));
 
         // When
         final Object result = function.apply(value);
@@ -236,14 +235,14 @@ public void shouldReturnAGivenTreeSet() {
     public void shouldConvertTreeSetToHashSet() {
         // Given
         final ToSet function = new ToSet(HashSet.class);
-        final Set value = new TreeSet(Sets.newHashSet("value1", "value2"));
+        final Set value = new TreeSet(new HashSet<>(Arrays.asList("value1", "value2")));
 
         // When
         final Object result = function.apply(value);
 
         // Then
         assertThat(result)
-                .isEqualTo(Sets.newHashSet(value))
+                .isEqualTo(new HashSet<>(value))
                 .isExactlyInstanceOf(HashSet.class)
                 .asInstanceOf(COLLECTION)
                 .containsExactlyInAnyOrderElementsOf(value);
@@ -253,7 +252,7 @@ public void shouldConvertTreeSetToHashSet() {
     public void shouldConvertHashSetToTreeSet() {
         // Given
         final ToSet function = new ToSet(TreeSet.class);
-        final Set value = Sets.newHashSet("value1", "value2");
+        final Set value = new HashSet<>(Arrays.asList("value1", "value2"));
 
         // When
         final Object result = function.apply(value);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToTupleTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToTupleTest.java
index 1b2ce644b..54a6932ed 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToTupleTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/function/ToTupleTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 Crown Copyright
+ * Copyright 2019-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.function;
 
-import com.google.common.collect.Lists;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.junit.jupiter.api.Test;
@@ -29,6 +28,7 @@
 import uk.gov.gchq.koryphe.util.JsonSerialiser;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -42,7 +42,7 @@ public void shouldConvertListIntoArrayTuple() {
         final ToTuple function = new ToTuple();
 
         // When
-        Tuple output = function.apply(Lists.newArrayList(1, 2, 3, 4));
+        Tuple output = function.apply(Arrays.asList(1, 2, 3, 4));
 
         // Then
         assertThat(output).isEqualTo(new ArrayTuple(1, 2, 3, 4));
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/impl/predicate/IsInTest.java b/core/src/test/java/uk/gov/gchq/koryphe/impl/predicate/IsInTest.java
index dce0da847..7a7e68dcd 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/impl/predicate/IsInTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/impl/predicate/IsInTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.impl.predicate;
 
-import com.google.common.collect.Sets;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.predicate.PredicateTest;
@@ -26,6 +25,7 @@
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -69,7 +69,7 @@ public void shouldJsonSerialiseAndDeserialise() throws IOException {
 
         // Then 2
         assertThat(deserialisedFilter).isNotNull();
-        assertThat(deserialisedFilter.getAllowedValues()).containsExactlyElementsOf(Sets.newHashSet(controlData));
+        assertThat(deserialisedFilter.getAllowedValues()).containsExactlyElementsOf(new HashSet<>(Arrays.asList(controlData)));
     }
 
     @Override
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/iterable/ChainedIterableTest.java b/core/src/test/java/uk/gov/gchq/koryphe/iterable/ChainedIterableTest.java
index de675851f..f21d29b05 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/iterable/ChainedIterableTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/iterable/ChainedIterableTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,12 @@
 
 package uk.gov.gchq.koryphe.iterable;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.util.CloseableUtil;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -62,8 +62,8 @@ public void shouldWrapAllIterableOfIterables() {
         // Given
         final List<Integer> itr1 = Collections.singletonList(0);
         final List<Integer> emptyItr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = Arrays.asList(1, 2, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         // When
         final List<List<Integer>> collect = Stream.of(itr1, emptyItr2, itr3, itr4).collect(Collectors.toList());
@@ -79,8 +79,8 @@ public void shouldWrapAllArrayOfIterables() {
         // Given
         final List<Integer> itr1 = Collections.singletonList(0);
         final List<Integer> emptyItr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = Arrays.asList(1, 2, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         // When
         final ChainedIterable<Integer> wrappedItr = new ChainedIterable<>(itr1, emptyItr2, itr3, itr4);
@@ -94,9 +94,9 @@ public void shouldWrapAllArrayOfIterablesWithNulls() {
         // Given
         final List<Integer> itr1 = Collections.singletonList(0);
         final List<Integer> emptyItr2 = new ArrayList<>(0);
-        final List<Integer> itrWithNull = Lists.newArrayList((Integer) null);
-        final List<Integer> itr3 = Lists.newArrayList(1, null, 2, null, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itrWithNull = Arrays.asList((Integer) null);
+        final List<Integer> itr3 = Arrays.asList(1, null, 2, null, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         // When
         final ChainedIterable<Integer> wrappedItr = new ChainedIterable<>(itr1, emptyItr2, itrWithNull, itr3, itr4);
@@ -110,8 +110,8 @@ public void shouldHandleNullsOfIterables() {
         // Given
         final List<Integer> itr1 = Collections.singletonList(0);
         final List<Integer> emptyItr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = Arrays.asList(1, 2, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         // When
         final ChainedIterable<Integer> wrappedItr = new ChainedIterable<>(null, itr1, null, emptyItr2, null, itr3, itr4);
@@ -124,10 +124,10 @@ public void shouldHandleNullsOfIterables() {
     @Test
     public void shouldRemoveElementFromFirstIterable() {
         // Given
-        final List<String> itr1 = Lists.newArrayList("a");
+        final List<String> itr1 = new ArrayList<>(Arrays.asList("a"));
         final List<String> emptyItr2 = new ArrayList<>(0);
-        final List<String> itr3 = Lists.newArrayList("b", "c", "d", "e");
-        final List<String> itr4 = Lists.newArrayList("f", "g");
+        final List<String> itr3 = Arrays.asList("b", "c", "d", "e");
+        final List<String> itr4 = Arrays.asList("f", "g");
 
         ChainedIterable<String> wrappedItr = null;
         Iterator<String> itr = null;
@@ -154,10 +154,10 @@ public void shouldRemoveElementFromFirstIterable() {
     @Test
     public void shouldRemoveElementFromThirdIterable() {
         // Given
-        final List<String> itr1 = Lists.newArrayList("a");
+        final List<String> itr1 = Arrays.asList("a");
         final List<String> emptyItr2 = new ArrayList<>(0);
-        final List<String> itr3 = Lists.newArrayList("b", "c", "d", "e");
-        final List<String> itr4 = Lists.newArrayList("f", "g");
+        final List<String> itr3 = new ArrayList<>(Arrays.asList("b", "c", "d", "e"));
+        final List<String> itr4 = Arrays.asList("f", "g");
 
         // When
         ChainedIterable<String> wrappedItr = null;
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/iterable/FilteredIterableTest.java b/core/src/test/java/uk/gov/gchq/koryphe/iterable/FilteredIterableTest.java
index c7adf2f6a..cb6516e2c 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/iterable/FilteredIterableTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/iterable/FilteredIterableTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,12 @@
 
 package uk.gov.gchq.koryphe.iterable;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.impl.predicate.IsLessThan;
 import uk.gov.gchq.koryphe.impl.predicate.IsMoreThan;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Predicate;
 
@@ -32,23 +32,23 @@ public class FilteredIterableTest {
 
     @Test
     public void shouldThrowIAXWhenArrayOfIterablesIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(null, Lists.newArrayList(new IsLessThan(4))));
+        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(null, Arrays.asList(new IsLessThan(4))));
     }
 
     @Test
     public void shouldThrowIAXWhenListOfPredicatesIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(Lists.newArrayList(1, 2, 3, 4, 5), (List) null));
+        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(Arrays.asList(1, 2, 3, 4, 5), (List) null));
     }
 
     @Test
     public void shouldThrowIAXWhenOnePredicateIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(Lists.newArrayList(1, 2, 3, 4, 5), Lists.newArrayList(new IsLessThan(4), (Predicate) null)));
+        assertThatIllegalArgumentException().isThrownBy(() -> new FilteredIterable(Arrays.asList(1, 2, 3, 4, 5), Arrays.asList(new IsLessThan(4), (Predicate) null)));
     }
 
     @Test
     public void shouldCorrectlyFilterSinglePredicate() {
         // Given
-        final List<Integer> itr = Lists.newArrayList(1, 2, 3, 4, 5);
+        final List<Integer> itr = Arrays.asList(1, 2, 3, 4, 5);
 
         // When
         FilteredIterable<Integer> filteredIterable = new FilteredIterable<Integer>(itr, new IsLessThan(4));
@@ -60,8 +60,8 @@ public void shouldCorrectlyFilterSinglePredicate() {
     @Test
     public void shouldCorrectlyFilterMultiplePredicates() {
         // Given
-        final List<Integer> itr = Lists.newArrayList(1, 2, 3, 4, 5);
-        final List<Predicate> predicates = Lists.newArrayList(new IsLessThan(4), new IsMoreThan(1));
+        final List<Integer> itr = Arrays.asList(1, 2, 3, 4, 5);
+        final List<Predicate> predicates = Arrays.asList(new IsLessThan(4), new IsMoreThan(1));
 
         // When
         FilteredIterable<Integer> filteredIterable = new FilteredIterable<Integer>(itr, predicates);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/iterable/MappedIterableTest.java b/core/src/test/java/uk/gov/gchq/koryphe/iterable/MappedIterableTest.java
index e541993ff..7e6f1e478 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/iterable/MappedIterableTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/iterable/MappedIterableTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,12 @@
 
 package uk.gov.gchq.koryphe.iterable;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import uk.gov.gchq.koryphe.impl.function.Increment;
 import uk.gov.gchq.koryphe.impl.function.MultiplyBy;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
@@ -32,23 +32,23 @@ public class MappedIterableTest {
 
     @Test
     public void shouldThrowIAXWhenArrayOfIterablesIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(null, Lists.newArrayList(new Increment(4))));
+        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(null, Arrays.asList(new Increment(4))));
     }
 
     @Test
     public void shouldThrowIAXWhenListOfFunctionsIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(Lists.newArrayList(1, 2, 3, 4, 5), (List) null));
+        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(Arrays.asList(1, 2, 3, 4, 5), (List) null));
     }
 
     @Test
     public void shouldThrowIAXWhenOneFunctionIsNull() {
-        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(Lists.newArrayList(1, 2, 3, 4, 5), Lists.newArrayList(new Increment(4), (Function) null)));
+        assertThatIllegalArgumentException().isThrownBy(() -> new MappedIterable(Arrays.asList(1, 2, 3, 4, 5), Arrays.asList(new Increment(4), (Function) null)));
     }
 
     @Test
     public void shouldCorrectlyApplySingleFunction() {
         // Given
-        final List<Integer> itr = Lists.newArrayList(1, 2, 3, 4, 5);
+        final List<Integer> itr = Arrays.asList(1, 2, 3, 4, 5);
 
         // When
         MappedIterable<Integer, Integer> mappedIterable = new MappedIterable<Integer, Integer>(itr, new Increment(4));
@@ -60,8 +60,8 @@ public void shouldCorrectlyApplySingleFunction() {
     @Test
     public void shouldCorrectlyApplyMultipleFunctions() {
         // Given
-        final List<Integer> itr = Lists.newArrayList(1, 2, 3, 4, 5);
-        final List<Function> functions = Lists.newArrayList(new Increment(4), new MultiplyBy(2));
+        final List<Integer> itr = Arrays.asList(1, 2, 3, 4, 5);
+        final List<Function> functions = Arrays.asList(new Increment(4), new MultiplyBy(2));
 
         // When
         MappedIterable<Integer, Integer> mappedIterable = new MappedIterable<Integer, Integer>(itr, functions);
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/signature/InputValidatorAssert.java b/core/src/test/java/uk/gov/gchq/koryphe/signature/InputValidatorAssert.java
index 4d40ad98b..cb317ade1 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/signature/InputValidatorAssert.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/signature/InputValidatorAssert.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,11 @@
 
 package uk.gov.gchq.koryphe.signature;
 
-import com.google.common.collect.Sets;
-
 import org.assertj.core.api.AbstractAssert;
 
+import java.util.Arrays;
+import java.util.HashSet;
+
 public class InputValidatorAssert extends AbstractAssert<InputValidatorAssert, InputValidator> {
 
     public InputValidatorAssert(InputValidator actual) {
@@ -33,7 +34,7 @@ public static InputValidatorAssert assertThat(InputValidator actual) {
     public InputValidatorAssert acceptsInput(Class<?>... arguments) {
         isNotNull();
         if (!actual.isInputValid(arguments).isValid()) {
-            failWithMessage("Expected Class %s to accept inputs %s", actual, Sets.newHashSet(arguments));
+            failWithMessage("Expected Class %s to accept inputs %s", actual, new HashSet<>(Arrays.asList(arguments)));
         }
         return this;
     }
@@ -41,7 +42,7 @@ public InputValidatorAssert acceptsInput(Class<?>... arguments) {
     public InputValidatorAssert rejectsInput(Class<?>... arguments) {
         isNotNull();
         if (actual.isInputValid(arguments).isValid()) {
-            failWithMessage("Expected Class %s to reject inputs %s", actual, Sets.newHashSet(arguments));
+            failWithMessage("Expected Class %s to reject inputs %s", actual, new HashSet<>(Arrays.asList(arguments)));
         }
         return this;
     }
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/signature/SignatureAssert.java b/core/src/test/java/uk/gov/gchq/koryphe/signature/SignatureAssert.java
index f0e00f70a..0f8088433 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/signature/SignatureAssert.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/signature/SignatureAssert.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Crown Copyright
+ * Copyright 2022-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,11 @@
 
 package uk.gov.gchq.koryphe.signature;
 
-import com.google.common.collect.Sets;
-
 import org.assertj.core.api.AbstractObjectAssert;
 
+import java.util.Arrays;
+import java.util.HashSet;
+
 public class SignatureAssert extends AbstractObjectAssert<SignatureAssert, Signature> {
 
     public SignatureAssert(Signature actual) {
@@ -33,7 +34,7 @@ public static SignatureAssert assertThat(Signature actual) {
     public SignatureAssert isAssignableFrom(Class<?>... arguments) {
         isNotNull();
         if (!actual.assignable(arguments).isValid()) {
-            failWithMessage("Expected Signature %s to be assignable from %s", actual, Sets.newHashSet(arguments));
+            failWithMessage("Expected Signature %s to be assignable from %s", actual, new HashSet<>(Arrays.asList(arguments)));
         }
         return this;
     }
@@ -41,7 +42,7 @@ public SignatureAssert isAssignableFrom(Class<?>... arguments) {
     public SignatureAssert isNotAssignableFrom(Class<?>... arguments) {
         isNotNull();
         if (actual.assignable(arguments).isValid()) {
-            failWithMessage("Expected Signature %s not to be assignable from %s", actual, Sets.newHashSet(arguments));
+            failWithMessage("Expected Signature %s not to be assignable from %s", actual, new HashSet<>(Arrays.asList(arguments)));
         }
         return this;
     }
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/tuple/ArrayTupleTest.java b/core/src/test/java/uk/gov/gchq/koryphe/tuple/ArrayTupleTest.java
index e834d18a3..82c617930 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/tuple/ArrayTupleTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/tuple/ArrayTupleTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,10 @@
 
 package uk.gov.gchq.koryphe.tuple;
 
-import com.google.common.collect.Lists;
-
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class ArrayTupleTest {
@@ -44,6 +44,6 @@ public void testInitialArrayConstructors() {
         final ArrayTuple tuple = new ArrayTuple(initialValues);
 
         // Then
-        assertThat(tuple).containsExactlyElementsOf(Lists.newArrayList(initialValues));
+        assertThat(tuple).containsExactlyElementsOf(Arrays.asList(initialValues));
     }
 }
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/util/IterableUtilTest.java b/core/src/test/java/uk/gov/gchq/koryphe/util/IterableUtilTest.java
index 50081012c..8f4420fcb 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/util/IterableUtilTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/util/IterableUtilTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.util;
 
-import com.google.common.collect.Lists;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -35,8 +34,8 @@ public void shouldWrapAllIterables() {
         // Given
         final List<Integer> itr1 = Collections.singletonList(0);
         final List<Integer> itr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = Arrays.asList(1, 2, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         // When
         final Iterable<Integer> itrConcat = IterableUtil.concat(Arrays.asList(itr1, itr2, itr3, itr4));
@@ -48,10 +47,10 @@ public void shouldWrapAllIterables() {
     @Test
     public void shouldRemoveElementFromFirstIterable() {
         // Given
-        final List<Integer> itr1 = Lists.newArrayList(0);
+        final List<Integer> itr1 = new ArrayList<>(Arrays.asList(0));
         final List<Integer> itr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = Arrays.asList(1, 2, 3, 4);
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         final int itr1Size = itr1.size();
         final int itr2Size = itr2.size();
@@ -75,10 +74,10 @@ public void shouldRemoveElementFromFirstIterable() {
     @Test
     public void shouldRemoveElementFromThirdIterable() {
         // Given
-        final List<Integer> itr1 = Lists.newArrayList(0);
+        final List<Integer> itr1 = Arrays.asList(0);
         final List<Integer> itr2 = new ArrayList<>(0);
-        final List<Integer> itr3 = Lists.newArrayList(1, 2, 3, 4);
-        final List<Integer> itr4 = Lists.newArrayList(5, 6);
+        final List<Integer> itr3 = new ArrayList<>(Arrays.asList(1, 2, 3, 4));
+        final List<Integer> itr4 = Arrays.asList(5, 6);
 
         final int itr1Size = itr1.size();
         final int itr2Size = itr2.size();
diff --git a/core/src/test/java/uk/gov/gchq/koryphe/util/ReflectionUtilTest.java b/core/src/test/java/uk/gov/gchq/koryphe/util/ReflectionUtilTest.java
index cb72fbecf..684bbd3c2 100644
--- a/core/src/test/java/uk/gov/gchq/koryphe/util/ReflectionUtilTest.java
+++ b/core/src/test/java/uk/gov/gchq/koryphe/util/ReflectionUtilTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2020 Crown Copyright
+ * Copyright 2018-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,6 @@
 
 package uk.gov.gchq.koryphe.util;
 
-import com.google.common.collect.Sets;
 import com.google.common.primitives.UnsignedLong;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -24,6 +23,7 @@
 
 import uk.gov.gchq.koryphe.serialisation.json.obj.first.TestCustomNumber;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
@@ -105,11 +105,11 @@ public void shouldReturnSimpleClassNames() {
         assertThat(simpleClassNames)
                 .containsEntry(
                     TestCustomNumber.class.getSimpleName(),
-                    Sets.newHashSet(
+                    new HashSet<>(Arrays.asList(
                         TestCustomNumber.class,
                         uk.gov.gchq.koryphe.serialisation.json.obj.second.TestCustomNumber.class
                     )
-                )
+                ))
                 .doesNotContainKey(UnsignedLong.class.getSimpleName());
     }
 
@@ -137,11 +137,11 @@ public void shouldReturnSimpleClassNamesWithExtraClassesInPath() {
         assertThat(simpleClassNames)
                 .containsEntry(
                     TestCustomNumber.class.getSimpleName(),
-                    Sets.newHashSet(
+                    new HashSet<>(Arrays.asList(
                         TestCustomNumber.class,
                         uk.gov.gchq.koryphe.serialisation.json.obj.second.TestCustomNumber.class
                     )
-                )
+                ))
                 .containsEntry(
                     UnsignedLong.class.getSimpleName(),
                     Collections.singleton(UnsignedLong.class)
@@ -162,11 +162,11 @@ public void shouldReturnSimpleClassNamesWithExtraClassesInPathWithTrailingDot()
         assertThat(simpleClassNames)
                 .containsEntry(
                     TestCustomNumber.class.getSimpleName(),
-                    Sets.newHashSet(
+                    new HashSet<>(Arrays.asList(
                         TestCustomNumber.class,
                         uk.gov.gchq.koryphe.serialisation.json.obj.second.TestCustomNumber.class
                     )
-                )
+                ))
                 .containsEntry(
                     UnsignedLong.class.getSimpleName(),
                     Collections.singleton(UnsignedLong.class)
diff --git a/doc/src/main/java/uk/gov/gchq/koryphe/example/KorypheExample.java b/doc/src/main/java/uk/gov/gchq/koryphe/example/KorypheExample.java
index e7dddbf19..c10711a01 100644
--- a/doc/src/main/java/uk/gov/gchq/koryphe/example/KorypheExample.java
+++ b/doc/src/main/java/uk/gov/gchq/koryphe/example/KorypheExample.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 Crown Copyright
+ * Copyright 2017-2023 Crown Copyright
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,10 @@
 
 package uk.gov.gchq.koryphe.example;
 
-import com.google.common.collect.Lists;
-
 import uk.gov.gchq.koryphe.example.annotation.Example;
 import uk.gov.gchq.koryphe.tuple.MapTuple;
 import uk.gov.gchq.koryphe.tuple.Tuple;
+import uk.gov.gchq.koryphe.util.IterableUtil;
 
 import java.util.stream.Stream;
 
@@ -78,7 +77,7 @@ protected void printTuple(final Tuple tuple) {
     }
 
     protected <T> void printIterable(final Iterable<T> iterable) {
-        System.out.println(Lists.newArrayList(iterable));
+        System.out.println(IterableUtil.toList(iterable));
     }
 
     protected Tuple<String> createMapTuple(final Object valueA, final Object valueB, final Object valueC) {
diff --git a/pom.xml b/pom.xml
index 6790d2c43..3f4217f06 100644
--- a/pom.xml
+++ b/pom.xml
@@ -34,7 +34,7 @@
 
     <properties>
         <spotbugs.version>4.7.3</spotbugs.version>
-        <guava.version>29.0-jre</guava.version>
+        <guava.version>31.1-jre</guava.version>
         <assertj.version>3.22.0</assertj.version>
         <jackson.version>2.13.4</jackson.version>
         <junit5.version>5.8.2</junit5.version>
@@ -143,11 +143,6 @@
             <artifactId>commons-io</artifactId>
             <version>${commons-io.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-csv</artifactId>
@@ -190,6 +185,12 @@
             <version>${mockito.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+            <scope>test</scope>
+        </dependency>
 
         <!-- JSON Serialisation/De-serialisation dependencies -->
         <dependency>